How else to describe Leonard Nimoy's enduring, at times conflicted relationship with Star Trek, the franchise that's defined his career for more than four decades — regardless of how many times he swore it off or believed it was finished?

"Countless times, I thought it was done," he admits on the phone from Los Angeles.

But this time, says the 79-year-old actor-director-photographer, there are no more possibilities. Spock, his pointy-eared alter-ego, will live long and prosper. But it will be without Nimoy.